code: def __init__(self):
      super().__init__()
      self.flow_d = EmptyFlow()
      self.work_b = EmptyWork()
  
file_path: pytorch-lightning/docs/source-app/code_samples/quickstart/app_comp.py
imports: from lightning.app import LightningFlow, LightningApp
  from lightning.app.testing import EmptyFlow, EmptyWork
label_desc: Use image node_id 1 to create a new FlowB object from inherited base classes: LightningFlow with example: obj = FlowB()